<template>
    <ul class="app-header-nav">
        <li class="home"><RouterLink to="/">首页</RouterLink></li>
        <li v-for="item in list" :key="item.id" @mousemove="show(item)" @mouseleave="hide(item)">
            <RouterLink :to="`/category/${item.id}`" @click="hide(item)">{{item.name}}</RouterLink>
            <div class="layer" :class="{open:item.open}">
              <ul>
                <li v-for="sub in item.children" :key="sub.id">
                    <RouterLink :to="`/category/sub/${sub.id}`" @click="hide(item)">
                    <img :src="sub.picture" alt="">
                    <p>{{sub.name}}</p>
                    </RouterLink>
                </li>
              </ul>
            </div>
        </li>
    </ul>
</template>
<script>
import { computed } from 'vue'
import { useStore } from 'vuex'
export default {
    name: 'AppHeaderNav',
    setup () {
      const store = useStore()
      // 拿到vuex中的分类列表
      const list = computed(() => {
        return store.state.category.list
      })
      
    // 跳转的时候不会关闭二级类目，通过数据来控制
    // 1. vuex每个分类加上open数据
    // 2. vuex提供显示和隐藏函数，修改open数据
    // 3. 组件中使用vuex中的函数，使用时间来绑定，提供一个类名显示隐藏的类名
      const show = (item) => {
        store.commit('category/show',item)
      }
      const hide = (item) => {
        store.commit('category/hide',item)
      }

      return { list,show,hide }
    }
}
</script>
<style lang="less" scoped>
.app-header-nav {
    width: 820px;
    display: flex;
    justify-content: space-around;
    padding-left: 40px;
    position: relative;
    z-index: 999;
    > li {
      margin-right: 40px;
      width: 38px;
      text-align: center;
      > a {
        font-size: 16px;
        line-height: 32px;
        height: 32px;
        display: inline-block;
      }
      &:hover {
        > a {
          color: @xtxColor;
          border-bottom: 1px solid @xtxColor;
        }
        //显示二级类目
        // > .layer {
        // height: 132px;
        // opacity: 1;
        // }
      }
    }
}
//二级类名弹层
.layer {
  &.open {
    height: 132px;
    opacity: 1;
  }
  width: 1240px;
  background-color: #fff;
  position: absolute;
  left: -200px;
  top: 56px;
  height: 0;
  overflow: hidden;
  opacity: 0;
  box-shadow: 0 0 5px #ccc;
  transition: all .2s .1s;
  ul {
    display: flex;
    flex-wrap: wrap;
    padding: 0 70px;
    align-items: center;
    height: 132px;
    li {
      width: 110px;
      text-align: center;
      img {
        width: 60px;
        height: 60px;
      }
      p {
        padding-top: 10px;
      }
      &:hover {
        p {
          color: @xtxColor;
        }
      }
    }
  }
}
</style>